Article handling method and apparatus



Oct. 15, 1968 T. 1.. MILLICH 3,405,511

ARTICLE HANDLING METHOD AND APPARATUS Filed Oct. 24, 1965 4 Sheets-Sheet 1 INVENTOR.

THOMAS L. MILLICH BY [5M4b4N M- W L% ATTORNEYS 1968 'r. L. MILLICH 3,405,611

ARTICLE HANDLING METHOD AND APPARATUS Filed Oct. 24, 1965 4 Sheets-Sheet 2 FlG 3B FIGJA El 36 2| l9 xGl INVENTOR. THOMAS L. MILLICH BY WMKW+W ATTORNEYS Oct. 15, 1968 T. L. MILLICH 3,405,611

ARTICLE HANDLING METHOD AND APPARATUS Filed Oct. 24, 1965 4 Sheets-Sheet 5 INVENTOR.

THOMAS L. MILLICH MIMIRJLAMM ATTORNEYS Oct. 15, 1968 T. 1... MILLICH ARTICLE HANDLING METHOD AND APPARATUS 4 Sheets-Sheet 4 Filed Oct. 24, 1965 FlG 8 FIG 9 9 P 9\ w 8 mm 1 1 \Q 8 m G m 7 D 6 R LII X 6 w INVENTOR.

THOMAS L.. M ILLICH III ATTORNEYS United States Patent 3,405,611 ARTICLE HANDLING METHOD AND APPARATUS Thomas L. Millich, San Francisco, Calif., assignor of one-half to Paperbox Corporation, Oakland, Calif a corporation of California Filed Oct. 24, 1965, Ser. No. 504,703 12 Claims. (CI. 93-49) ABSTRACT OF THE DISCLOSURE A carton blank folding apparatus and method in which carton blanks are moved at a predetermined continuous speed past a folding station at which endless moving parallel chainsare provided, each of which has a folding lug' projecting therefrom. The lugs are positioned on the respective chains in spaced relationship so that a carton may be positioned therebetween at the folding station. Cam operated drive mechanism is provided in conjunction with the respective chains for selectively increasing and decreasing the speeds of travel of'the chains as the lugs move past the station so that the lugs sequentially are brought closer together and moved farther apart to effect folding of predetermined portions of the carton. Similar folding mechanisms are provided at a second station for performing folding operations on other foldable portions of the carton blank.

This invention relates generally to a method and to an apparatus for handling articles, such as fiat foldable sheets of which paperboard and like carton blanks are illustrative. More particularly, this invention relates to a method and to an apparatus for folding predetermined marginal portions of a flat sheet, such as panels and flaps of a preformed carton blank, relative to other portions of such sheet. Still more particularly, this invention relates to a method and to an apparatus for transforming a carton blank from a fiat unfolded condition into a folded readyto-erect condition.

While hereinafter reference is directed particularly to the handling of flat sheets, such as carton blanks, aspects of the article handling method and apparatus of this invention have utility in other fields which will become apparent to a person skilled in the art reading this disclosure. Accordingly, this invention is not intended to be limited solely to applicability in the specific field of utility disclosed herein, but is intended to include other analogous fields to which the disclosed handling apparatus and method are adaptable.

The apparatus and method of this invention are improvements over those disclosed in my earlier Patents No. 2,962,945 dated Dec. 6, 1960, and No. 3,055,276 dated Sept. 25, 1962. While the folding apparatus and methods of those patents are effective for their intended purpose, in each instance the sheet handling procedure disclosed therein entails a change in the path of travel of each sheet being handled during a folding operation, with attendant change or loss of speed. With the present invention, sheets being folded or other articles being handled are transferred at a generally constant speed through a fixed generally straight predetermined path without requiring any change in the path of travel or any modification in the speed of movement thereof during the handling procedure. Thus, a high speed, high efliciency operation is insured due to the improved features of this invention, such as the drive mechanism hereof which actuates article engaging members in a novel changingspeed fashion without requiring changes in speed of movement of the articles being handled.

From the foregoing it should be understood that objects of this invention include the following, among others:

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the provision of a method and an apparatus for handling a series of articles in sequence; the provision of a method and an apparatus for folding marginal portions of fiat sheets, such as carton blanks, in a fast and highly efficient procedure; the provision of a method and an apparatus for handling flat sheets, such as carton blanks, in continuous and uninterrupted fashion while the sheets are conveyed in a generally straight path without altering the direction of travel or speed of movement thereof; the provision of a method and an apparatus for handling flat sheets, such as carton blanks, to transform such blanks from the fiat condition to the completely folded condition ready for shipment or storage andsubsequent erection to receive a product therein; the provision in apparatus for handling moving articles, such as fiat sheets, of drive means and mechanisms adapted to act on marginal portions of such articles to engage leading and/or trailing portions thereof; and the provision in an article handling apparatus of wobble shaft structure for actuating one or more members in discontinuous fashion to effect engagement of each such member with a predetermined leading or trailing marginal portion of the article being handled without altering the speed of movement of such article.

These and other objects of this invention will become apparent from the following disclosure in which reference is directed to the appended drawings which illustrate the handling of fiat sheets, such as a series of paperboard carton blanks of a particular configuration. The particular carton blank illustrated is shown for illustrative purposes only and utility of this invention in conjunction with the handling of sheets different from that shown, and other articles as well, is contemplated within the scope of this invention.

In the drawings:

FIG. 1 is a plan view, partially cut away, of a portion of the subject apparatus, showing essential details only thereof for purposes of clarity.

FIG. 2 is a vertical sectional view, partially cut away, of the subject apparatus taken in the plane of line 2-2 of FIG. 1.

FIGS. 3A through 3F are plan views, somewhat schematic in nature, which show the sequence of transforming a sheet from the flat condition to the folded condition, and showing those portions of the subject apparatus which effect such folding in sequential steps at predetermined folding stations.

FIGS. 4A and 4B are generally schematic views of a portion of the apparatus which preliminarily folds certain predetermined opposed marginal portions of a sheet prior to introduction thereof into the main body of the apparatus.

FIGS. 5A through 5H are partially schematic side elevational views of portions of the apparatus showing the sequential operations performed thereby on sheets being handled in a sheet folding operation.

FIG. 6 is a vertical sectional view through the housing of an adjustable wobble shaft structure which activates folding members of the subject apparatus, taken in the plane of line 66 of FIG. 7.

FIG. 7 is a plan view of the adjustable wobble shaft structure with the cover of the housing thereof removed.

FIG. 8 is a vertical sectional view of the wobble shaft structure taken in the plane of line 8-8 of FIG. 6.

FIG. 9 is a vertical sectional view of the wobble shaft structure taken in the plane of line 9-9 of FIG. 6.

FIGS. 10A, 10B and 10C are vertical sectional views through the wobble shaft structure taken generally in the plane of line 8-8 of FIG. 6 which show various positions of adustment thereof.

FIG. 11 is a generally schematic view of the power source and drive means by which the respective wobble p 3 shaft structures are actuated in timed relationship with each other.

Before describing in detail the method and apparatus employed with this invention, reference is first directed to the folding sequence for a flat carton blank of a type well suited for handling by this invention, as illustrated in FIGS. 3A-through 3F. Such blank, when erected, defines an open-top tray carton of well known type. In this connection, it will be noted that the carton shown in the drawings corresponds generally to cartons shown in my aforementioned patents.

Such carton blank, generally designated 1, when flat comprises a rectangular body portion which defines the bottom panel 2 of the blank when erected. A first pair of opposed marginal portions to be folded comprise opposite rectangular side wall panels 3 and 4 hingedly connected along parallel fold lines 6 and 7 which form opposed margins of bottom panel 2. At opposite ends of each of side wall panels 3 and 4 are a pair of tabs, designatedS and 9 respectively. Tabs 8 and 9 are generally triangular in configuration and are hingedly connected by predetermined oblique fold lines 11 and 12 with their respective side wall panels 3 and 4.

A second pair of opposed side wall panels 13 and 14 are hingedly connected along fold lines 16 and 17 which define the other two opposed margins of bottom panel 2. To each of side wall panels 13 and 14 are hingedly connected other opposed marginal portions of the blank, namely a pair of flaps 18 and 19 hingedly connected with their associated side wall panels along fold lines 21 and 22 respectively. Fold lines 21 and 22 are effective continuations of the aforementioned fold lines 6 and 7.

As is seen from FIG. 3A, each of flaps 18 and 19 is free to be folded separately from the adjacent side wall panels 3 and 4 lying adjacent thereto because of cuts 23 which form continuations of fold lines 16 and 17 along which side wall panels 13 and 14 are connected with bottom panel 2. Cuts 23 terminate at the juncture of fold lines 21 and 22 with fold lines 16 and 17.

An open top tray carton of the type illustrated and described has many uses after its transformation to the fully erected state. One such use, described for illustrative purposes only, is the receipt of a food product, such as fresh or frozen seafood in the tray defined by the bottom panel and the four opposed side wall panels thereof. For such use, a filled carton would be overwrapped with a suitable material, such as cellophane or a heat sealable plastic of the type commonly employed in the food packaging industry.

As mentioned previously, an important feature of this invention resides in the fact that carton blanks of the type illustrated may be rapidly transformed from the flat condition to the fully folded condition by moving the blank, and a succeeding series of similar blanks, at a predetermined generally constant speed without interruption through a fixed generally straight path which requires no change in direction of travel. In this connection, a brief summary of the blank folding method will be described, further details of which will become apparent in the detailed description of the folding apparatus which will follow.

Prior to reaching a first folding station, each blank being folded preferably has had each of its opposed leading and trailing side wall panels 3 and 4 partially prefolded along their respective fold lines 6 and 7 to facilitate subsequent folding thereof and to preclude buckling thereof. Such prefolding results in such panels being angularly related to project somewhat upwardly relative to bottom panel 2, as seen in FIG. A. At the first folding station the prefolded side wall panels are engaged generally simultaneously by at least two, or more, opposed folding members between which the blank is positioned as it is conveyed to and past the folding station. That is, the folding members in effect straddle the carton so as to be in a position to contact the leading wall panel 3 and the trailing wall panel 4 during the folding operation. At this stage, the carton is held down on a supporting surface, preferably by engagement of the other side wall panels 13 and 14 and their connected flaps 18 and 19 by suitable holddown means.

The folding members employed at the first station are moved in the same direction as the moving carton blank and in synchronization with the continuous predetermined speed of movement of the carton. At the proper time a folding member adjacent the leading side wall panel 3 is brought into contact with such panel by decreasing the speed of movement of the folding member to a speed less than that of the moving carton so that leading side wall panel 3 is engaged by such member. Generally simultaneously, a folding member adjacent the trailing side wall panel 4 is brought into contact with such panel by increasing the speed of movement of the folding member to a speed which exceeds the speed of the moving carton. This speed reduction of the folding member in leading relationship in synchronization with speed increase of the folding member in trailing relationship results in such members contacting the wall panels 3 and 4 in scissors fashion to bring such panels into generally overlying and contacting relationship with respect to the bottom panel 2. By thus simultaneously modifying the speed of the folding members the normal spacing therebetween which permits them initially to straddle a carton blank is decreased, thereby restricting the carton therebetween so that folding of panels 3 and 4 is rapidly and automatically effected as seen in FIGS. 3B and 3C. As side wall panels 3 and 4 are being folded, each of the trianguuar tabs 8 and 9 connected therewith are simultaneously folded about their respective oblique fold lines 11 and 12 into overlying and generally contacting relationship with their respective side wall panels as seen in FIG. 3C for a purpose to be described.

With the carton blank in the partially folded condition shown in FIG. 3C, the blank is transferred at the same generally constant speed and without interruption or change in direction of travel thereof to a Second folding station at which additional folding operations are performed as seen in FIGS. 3D, 3E and 3F. At the second folding station the opposed pair of leading and trailing flaps 18 and 19 on each of side wall panels 13 and 14 are generally simultaneously engaged by a pair of folding members between which the carton is automatically located as the carton reaches the second folding station. These opposed pairs of folding members initially are spaced to straddle the carton and the flaps to be folded thereby in the same manner described previously. Thereafter, such pairs of folding members are actuated in the same simultaneous speed decrease-increase relationship described previously with respect to folding of side wall panels 3 and 4 so that each pair of opposed flaps 18 and 19 are folded about their respective fold lines into overlying generally contacting relationship with their respective associated side wall panels 13 and 14 as seen in FIG. 3E.

Subsequently, side wall panels 13 and 14, with their folded flaps 18 and 19 thereon, are folded over along their respective fold lines 16 and 17 into contacting relationship with the previously folded side wall panels 3 and4. This operation brings fiaps 18 and 19 into engagement with the previously folded triangular tabs 8 and 9 so that such fiaps and tabs may be secured together by adhesive or other suitable means in known fashion. In this connection, if adhesive is'to be employed for the securing function, portions thereof may be applied to the flaps 18 and 19 or tabs 8 and 9 just prior to transformation of the carton from the FIG. 3E condition to the FIG. 3F condition by any conventional adhesive applying procedure or apparatus (not shown).

With the carton blank transformed to the fully folded condition shown in FlG. 3?, it, and all succeeding cartons in a series following it, are ready for shipment or storage preparatory to use thereof for their intended purpose.

Having thus described briefly the folding method sequence, reference is now directed to the preferred embodiment of the apparatus illustrated herein which is well adapted to perform the just described folding operations.

By way of general summary, the apparatus includes the following component assemblies which cooperate and function in synchronization to effect folding of a series of successive blanks: conveyor means; folding means at a first folding station; second folding means at a second folding station; and drive means for actuating the respective folding means at the first and second folding stations. A suitable power source, or sources, for actuating the various component assemblies of the apparaus in timed relationship with each other also is provided. Also preferably used in conjunction with the apparatus and located at a prefolding station in advance of the first folding station is means for partially prefolding at least one pair of the opposed marginal portions of the carton blanks being handled.

The various component assemblies of the apparatus are mounted upon and supported by a pair of opposite side frame members 31 and 32 as seen in FIGS. 1 and 2. Such side frame members may rest upon the floor or other supporting surface of a building in which the apparatus is to be used. Located between the side frame members are the aforementioned first and second folding stations of the apparatus, generally designated 33 and 34 respectively in FIGS. 1 and 2. Both folding sta tions are serviced by the conveyor means of the apparatus which receives a series of flat cartons to be folded from a source of supply thereof (not shown) and transfers the same in slightly spaced sequential relationship at a generally continuous rate of speed to and past each of the folding stations.

The conveyor means employed is of the belt and supporting roller type, and at the first folding station comprises cooperable pairs of laterally spaced opposed upper and lower endless belts having frictional contact between adjacent reaches thereof. As seen in FIGS. 1 and 2, each of the upper belts of the respective pairs is designated 36 while each of the lower belts is designated 37.

The aligned upper and lower conveyor belts are also seen in FIGS. 3A, 3B and 3C. As also seen in those figures, the lateral spacing between the pairs of upper and lower belts is determined in accordance with the dimensions of the carton blanks being conveyed thereby. In this regard, each carton blank is conveyed to and past the first folding station by engagement of the upper and lower surfaces of opposed side wall panels 13 and 14 and their hingedly connected flaps 18 and 19 between the respective belts 36 and 37. This conveying arrangement thus leaves the other side wall panels 3 and 4 free of interference during folding at the first folding station.

Referring to FIGS. 2, A and 5B, each of the upper belts 36 has the limits of its path defined by spaced pulleys 38 which are mounted for rotation on supporting shafts 39 which extend between and are positioned in suitable bearings 41 (FIG. 1) secured to the side frame members 31 and 32 of the apparatus. If desired, idler pulleys 42 (FIG. 2) and adjustable belt tensioning devices 43 (FIG. SA) of known type may be employed in conjunction with the upper belts to maintain the desired tension thereon. Each of the lower belts 37 has its path defined by a pair of spaced pulleys 44 mounted for rotation on supporting shafts 46 which also extend between and are supported by bearings on the side frame members of the apparatus. In this connection, referring to FIGS. 5A and 5B, the respective pulleys 39 and 44 may be mounted by means of suitable brackets 47 on secondary side frame members designated 48 which extend parallel to the primary frame members 31 and 32 and which are supported intermediate thereof in any suitable known fashion.

Preferably, so that this apparatus may be employed to fold carton blanks of varying dimensions, the position of the mounting structure which supports belts 36 and 37 may be varied laterally. Similarly, other mechanisms described hereinafter may be selectively moved as required to adapt the apparatus for use with other size blanks.

As seen in FIGS. 2, 5A and 5B, preferably a series of idler rollers 51 extend transversely of the apparatus along the length thereof to assist in supporting the conveyor belts and to provide a supporting surface for the series of cartons carried therebetween. The rollers 51 have not been shown in FIG. 1 so that other details of construction might be shown therein more clearly.

While no drive means for the conveyor means has been specifically shown, it should be understood that the belts are driven at the same speed but in opposite directions to have the desired effect of drawing cartons fed thereto therebetween without twisting or otherwise deforming the cartons or conveying the same in other than a straight direction to and past the first folding station. The belts can be driven at the desired speed merely by connecting a power source with shafts 39 or 46 on which the pulleys 38 and 44 are mounted.

The conveyor means at the second folding station comprises another pair of upper and lower belts 52 and 53 which are driven directly by the aforementioned belts 36 and 37. This interdrive is accomplished by means of a pair of upper and lower pulleys 54 and 56 (FIG. 5B) which define one end of the path of the belts and which are mounted on and driven in response to rotation of shafts 39 and 46 on which the aforementioned pulleys 38 and 44 are mounted. Belts 52 and 53 are mounted centrally between side frame members 31 and 32 and are located to engage the folded side wall panels 3 and 4 of a carton, without contacting the triangular tabs 8 and 9 thereon, as seen in FIGS. 3D, 3E and SF.

Thus, after initial folding of the side wall panels 3 and 4, the conveyor means releases the other side wall panels 13 and 14 and their associated flaps 18 and 19 so that folding of such flaps and such side wall panels may be effected at the second folding station without interference from the conveyor means. Although not shown in the drawings, it should be understood that belts 52 and 53 pass over another pair of pulleys corresponding to pulleys 54 and 56 at the other end of their closed path to the left of FIGS. 1 and 2. Because belts 52 and 53 are driven directly by belts 36 and 37, constant conveyor speed throughout the apparatus is assured. As seen in FIG. 2, preferably a series of idler rollers 51 also are provided at the second folding station to support the respective belts 52 and 53 and carton blanks carried there by.

Folding means to be described are provided at each of the folding stations, and such means have been designated generally 61 at the first folding station and 62 at the second folding station. See FIG. 1. It has been found preferable, to facilitate folding of the large leading and trailing side wall panels 3 and 4, if such panels are partially prefolded prior to delivery thereof to the first folding station.

In this regard, reference is directed to FIGS. 4A and 4B for a generally schematic showing of means for effecting such partial prefolding of side wall panels 3 and 4. In this regard, paddle wheel structure, generally designated 63, is provided at a location somewhat in advance of the first folding station which comprises upper and lower rolls 64 and 66 mounted respectively for rotation with their supporting shafts 67 and 68 which are driven from any suitable power source (not shown), such as the power source for the conveyor means just described. Because such paddle wheel structure has been known generally in the art heretofore, extensive details '2 of the construction thereof have neither been shown nor described. But, as should be obvious from FIGS. 4A and 4B, the function of such paddle wheels is to bend upwardly in sequence first the leading side wall panel 3 of each carton blank fed therepast by suitable conveyor means, and subsequently to fold upwardly the trailing side wall panel 4. As seen in FIG. 4A, the rolls 64 and 66 are driven in unison and at the same speed but in opposite directions by meshed gears 70 provided in conjunction with each shaft 67 and 68.

The upper roll 64 is provided with one or more than one laterally spaced fingers 69 which project generally radially from the periphery thereof. Similarly, the bottom roller 66 is provided with one or more than one laterally spaced fingers 71 which similarly project radially from the periphery thereof. Bottom fingers 71 are of slightly greater length than upper fingers 69. The upper and lower rolls are driven by gears 70 in synchronization with each other so that as a carton blank to be prefolded is fed therepast at least one upper finger 69 contacts the upper surface of bottom panel 2 adjacent the fold line 6 by means of which the leading side wall panel 3 is connected to the bottom panel. Such engagement holds the carton blank on the supporting surface or conveyor means (not shown) along which the carton blank is moving.

At substantially the same time but slightly in advance of engagement of the blank by top fingers 69, at least one of the bottom fingers 71 has engaged the undersurface of side wall panel 3 and cooperates with the top fingers 69 in effecting upward folding of the side wall panel about its fold line 6. Such cooperation is seen in FIG. 4A.

Following prebending of the leading side wall panel 3, the carton blank is moved from the position shown in FIG. 4A to the position shown in FIG. 4B, at which time the upper surface of the trailing side wall panel 4 is engaged by a top finger 69 slightly in advance of engagement of the undersurface of that panel by a bottom finger 71. Thus, the cooperable fingers effect folding of the trailing side wall panel 4 upwardly about its hinge line 7.

In the embodiment shown in the drawings diametrically opposed fingers spaced 180 degrees from each other are provided on each of the rolls 64 and 66. However, it should be understood that the number and spacing of the fingers on each roll is determined primarily by the dimensions of the carton to be prefolded thereby. Thus, for larger size cartons only one finger may be employed on each roller while for smaller cartons of smaller dimension three or more fingers, more closely oriented than 180 degrees apart, may be required.

Following prefolding, each blank of the series being folded is fed in sequence to the first folding station 33 at which the folding operation of the side wall panels 3 and 4 is fully effected by the aforementioned folding means designated 61. In this connection, as seen in FIG. 5A, generally the prefolded side wall panels 3 and 4 extend upwardly at a slight angle relative to the plane of the remaining portions of the carton blank and thereby facilitate engagement thereof with the folding means at the first folding station.

Folding means 61 is actuated in sequential fashion as each blank of a series of blanks is fed therepast by conveyor belts 36 and 37. Such folding means, as FIGS. 5A through 5E illustrate, comprises at least one pair of longitudinally spaced folding lug members 73 and 74. Two cooperable pairs of lug members preferably are used, each of which is mounted on one of two spaced pairs of side by side chains 76 and 77, as seen in FIGS. 1, 3A, 3B and 3C. Each folding lug is generally hook shaped and projects from a side of its associated chain upwardly a distance sufficient to insure engagement of each such lug with a wall panel to be folded thereby. In this connection, as seen in FIG. 5C, each lug has a portion thereof which extends generally parallel to its associated chain and is spaced therefrom a sufficient distance so that the lug may be received completely over the wall panel being folded thereby to insure that such wall panel is folded into contacting relationship with the underlying bottom panel 2. of the carton blank.

In the embodiment shown in the drawings, each of chains 76 and 77 carries two lugs thereon so that one lug is engaging a carton along the top reach of the chain while the other lug is moving into position on the bottom reach of the chain. Note the positions of lugs 73 in FIG. 5B. However, depending upon the size of carton blanks being handled by the apparatus, more than or less than the number of lugs shown may be provided on each chain. Preferably each lug is detachably connected with its associated chain so that the spacing between adjacent lugs may be varied as required.

While two spaced cooperable pairs of side by side chains are preferred, hereinafter reference will be directed to the operation of only one such pair of chains and to the cooepration which exists between one lug 73 on one chain and an associated lug 74 on the other chain. The operation of the other pair of chains and their construction are identical to the following described features.

Chain 76, which carries lug 73, at one end of its run passes over a toothed sprocket 78 (FIGS. 1 and 5A) mounted on and keyed to a drive shaft 79 by a key 81. Adjacent chain 77, which carries lug 74, passes over a similar toothed sprocket 80 but such sprocket is not keyed to shaft 79 (FIG. 1) but is merely freely rotatable thereon and independently thereof. However, at the other end of its run chain 77 passes over a toothed sprocket 82 mounted on a drive shaft 83 (FIGS. 1 and 5B) which is secured thereto for rotation therewith by a key 84. At shaft 83, the aforementioned chain 76 passes over a similar toothed sprocket 85 but such sprocket is not keyed to the shaft 83 (FIG. 1) and is free to rotate thereon independently thereof.

Chains 76 and 77 are driven in the same direction upon rotation of shafts 79 and 83, and in synchronization with feeding of a series of cartons thereto, by drive means to be described later, but the speed at which such chains are driven, and therefore the speed of the lugs carried thereon, may be varied relative to each other and also relative to the predetermined speed at which the cartons are conveyed past the folding station. It is this feature of selective speed modification of the lug chains in accordance with a predetermined plan which creates the novel folding aspects of this invention.

It should be noted from FIG. 3A that lug 73 on chain 76 normally is spaced from and in trailing relationship relative to a cooperating lug 74 on adjacent chain 77. Such spacing is greater than the maximum dimension of the carton blank being handled so that the carton blank may be fed between such pair of spaced lugs as a blank reaches the first folding station. The drive means to be described effects selective change in the spacing between the cooperable lugs to produce the desired folding results. It should also be noted, see FIGS. 5A and 58, that the trailing lug 73 has the curved portion of its body extending in the direction of movement of the chains while the leading lug 74 has its curved body portion extending opposite to the direction of chain movement.

Conveyor belts 36 and 37 and chains 76 and 77 are driven in timed relationship with each other so that a lug 74 is carried by its associated chain into the path of but in advance of a carton blank to be folded thereby. After lug 74 has been placed in the path of the carton, trailing lug 73 on the other chain is positioned behind the carton so that the lugs straddle the carton as seen in FIG. 3A. At this particular time in the folding operation the lugs are being temporarily driven by their drive means at generally the same speed as the speed of travel of the blank. However, such speed relationship is only of sufficient duration to allow the lugs to be properly positioned adjacent the respective leading and trailing side wall panels 3 and 4 to be folded by the lugs.

Thereafter, the speed of chain 77 on which leading lug 74 is mounted is decreased relative to and below the constant carton speed while the speed of the chain 76 on which trailing lug 73 is mounted is simultaneously increased relative to and above the constant carton speed. This speed change has the effect of drawing the lugs toward each other in the direction of the arrows in FIG. 3B so that the spacing between the lugs is decreased. This spacing reduction results in the carton blank being caught in a scissors action between the two lugs as seen in FIG. 5B so that side wall panels 3 and 4 are engaged by the lugs and are folded inwardly toward each other into generally overlying contacting relationship with the bot tom panel 2, as seen in FIGS. 5B and 5C, and in FIGS. 3B and 3C.

As mentioned previously during this folding operation the conveyor belts 36 and 37 hold opposite margins of the carton down by their engagement with side wall panels 13 and 14 and their associated flaps 18 and 19.

With a carton blank of the type illustrated it is also preferred to fold back each of the triangular tabs 8 and 9 connected with the side wall panels 3 and 4 at the time such panels are folded as just described. To this end a plow member 36 is positioned in the path of each of the triangular tabs 8 and 9, as seen perhaps best in FIGS. 3C and 5C. Each such plow member is adjustably mounted in an adjustable bracket 87 bolted or otherwise secured to the aforementioned secondary frame member 48 of a the apparatus.

Each plow member 86 extends downwardly and inwardly towards the longitudinal axis of the apparatus. Due to this configuration and orientation, each of the trailing triangular tabs 9 is easily engaged beneath an associated plow member 86 as seen in FIG. 5C and bent backwards thereby into overlying relationship with its associated side wall panel 4 as the side wall panel is folded by lug 73. The leading triangular tabs 8 are folded by the plow members 86 in generally the same manner. As seen in FIG. 5B, when lug 74 strikes and moves upwardly the leading side wall panel 3, such upward movement engages each of the triangular tabs 9 with its associated plow member to effect folding back of the tab as the panel is folded upwardly and inwardly by lug 74. Folding of the tabs 8 and 9 in conjunction with folding of panels 3 and 4 is also shown in FIG. 3B, from which the plows have been omitted for purposes of clarity.

Following tab folding, the carton is ready to be discharged from the first folding station to the second folding station. However, to hold down the carton side wall panels 3 and 4, another plow member 88 mounted by a bracket 89 on the aforementioned secondary frame member 48 is provided as seen in FIG. 5D. Conveyor belts 36 and 37 carry the carton beneath plow member 88 so that side wall panels 3 and 4 are held down thereby. At that time the speed of each leading lug 74 is increased while the speed of each trailing lug 73 is simultaneously decreased so that the carton is freed of engagement by those lugs. Then the carton passes between conveyor belts 52 and 53 mounted centrally of the apparatus at the second folding station. At that time, the carton clears belts 36 and 37 so that the side wall panels 13 and 14 and their associated flaps 18 and 19 are free to be folded.

Other folding means are provided at the second folding station 34 and such other means includes two additional pairs of side by side endless chains 91 and 92 (FIGS. 3D and 3E) each of which passes over sprockets which are alternately keyed by keys 93 and 94 to a pair of spaced drive shafts 96 and 97, as perhaps best seen in FIG. 1, for the same purpose described previously with respect to chains 76 and 77. Each pair of chains 91 and 92 is mounted in line with the side wall panels 13 and 14 and the associated flaps 18 and 19 of the carton being handled.

Each chain 91 has one or more folding lugs 96 thereon of the type described previously while each of the other chains 92 has one or more similar folding lugs 97 thereon as seen in FIGS. 3D and 3E. Each lug 96 on chain 91 has the same spaced relationship with respect to its associated lug 97 on chain 92 as mentioned previously with respect to the cooperable lugs at the first folding station. Thus, as a patrially folded carton is conveyed by the conveyor belts 52 and 53 to the second folding station and therepast, each pair of cooperable lugs 96 and 97 are positioned generally in straddling relationship relative to the leading and trailing flaps 18 and 19 to be engaged therewith and folded thereby.

The sequence of operation at the second folding station is basically the same as that described previously at the first folding station with each pair of cooperable lugs 96 and 97 travelling initially at essentially the same speed as the carton, followed by a decrease in the speed of the leading lug 97 and a simultaneous increase in the speed of the trailing lug 96, to effect a scissors type folding of the flaps engaged thereby as the distance between the lugs is progressively decreased, as seen in FIGS. 3D, 3E, 5F and 5G.

While some prefolding of the leading and trailing flaps 18 and 19 could be effected if desired, it has been found that at the second folding station such prefolding is not required and that by proper predetermined orientation of the leading and trailing lugs 97 and 96 as seen in FIGS. 5F and 56, effective folding may be completed without employing such prefolding. In this connection, the spacing and timed relationship of the movement of the lugs 96 and 97 relative to a carton positioned therebetween is such that the leading lug 97 is placed in position and generally urges upwardly and rearwardly a leading flap 18 prior to engagement of the trailing lug 96 with trailing flap 19 from therebeneath, as seen in FIG. 5F. Thus, upon the speed change relationship mentioned, a rapid folding may be effected because the lugs 96 and 97 need travel a shorter distance than did the aforementioned lugs 73 and 74. That is, the spacing need be decreased a lesser amount with respect to the flap folding lugs 96 and 97 than was the case with respect to the panel folding lugs 73 and 74.

After the respective leading and trailing flaps 18 and 19 at each end of the carton have been folded over into engagement with their associated side wall panels 13 and 14 as seen in FIG. 3E, the speed of leading lug 97 is increased and the speed of trailing lug 96 is decreased to move the lugs away from each other to free the carton.

Then the conveyor belts 52 and 52 carry the carton into engagement with conventional plow devices generally designated 99 in FIGS. 5F and 5G and illustrated schematically by the dotted lines in FIG. 3F, which effect folding over of the side wall panels 13 and 14 about their respective fold lines 16 and 17 in conventional and well known fashion. As mentioned previously, if the carton is to be adhesively secured, suitable adhesive may be applied to the flaps 18 and 19 or to their associated tabs 8 and 9 in any conventional fashion just prior to plowing over of the side wall panels 13 and 14 to the FIG. 3F position.

Following such adhesive application, if any, the folded cartons are fed in succession by the conveyor belts 52 and 53 directly into a narrow elongated chute generally designated 101. Each succeeding folded carton 1 of the series urges the preceding cartons to the discharge end of the chute for handling in known fashion for stacking and shipment or storage.

The drive means which actuates the lug chains at the folding stations in the fashion described includes driving mechanism designed to impart the speed change modifications to the chains and lugs carried thereby in synchronization with movement of a series of spaced cartons to and past the first and second folding stations. In this regard, four such drive mechanisms, generally designated 106, 107, 108 and 109 respectively, as seen in FIGS. 1 and 2 are provided. In all essential details each of such drive mechanisms is identical with the other and hereinafter only details of one mechanism will be described. It should be understood, however, referring to FIGS. 1 and 2 that mechanism 106 drives shaft 79 and the lug chains keyed thereto; mechanism 107 drives shaft 83 and the lug chains keyed thereto; mechanism 108 drives shaft 96 and the lug chains keyed thereto; and mechanism 109 drives shaft 97 and the lug chains keyed thereto.

Each drive mechanism, as seen in FIGS. 1, 2 and 11 is driven from a main power source preferably in the form of an electric motor 111 of suitable capacity. The output shaft 112 of such motor has a sprocket 113 mounted on its end over which drive chain 114 passes into engagement with double sprockets 116 and 117 engaged with the drive mechanisms 107 and 108. These sprockets in turn, through other drive chains 118 and 119, actuate the other drive mechanisms 106 and 109. Thus, all drive mechanisms of the drive means of this apparatus are actuated by one power source and in direct timed relationship with each other and with travel of the cartons in sequence along the conveyor means. In this regard, if desired the conveyor means may be driven by the main motor 111 or some other separate power source may be employed.

Referring to FIGS. 1 and 2, and before describing details of a drive mechanism, it should be noted that each of the respective drive mechanisms 106, 107, 108 and 109 is operatively connected by means of an associated drive chain, 126, 127, 128 and 129 respectively, with the aforementioned shafts 81, 83, 96 and 97 about which the lug carrying chains of the folding means pass. Thus, each of the drive mechanisms actuates one of the shafts and the lug chains keyed therewith so that their speed may be sequentially altered as required during a folding olperation. Preferably, conventional tension devices generally designated 131 (FIG. 2) are provided in conjunction with each of the just mentioned drive chains to maintain the desired amount of tension thereon for most effective operation.

Referring now to FIGS. 6 through 9 and FIGS. A through 10C details of a representative drive mechanism 107 will be described.

Such drive mechanism, because of its adjustable nature, is termed herein a wobble shaft structure and comprises an adjustable bearing block 136 mounted for lateral sliding movement on pairs of lower and upper guide rails 137 and 138 in a leak proof housing designated generally 139. Extending through the bearing block is a drive shaft 141 which projects from opposite ends of the bearing block. One end 142 of the shaft 141 projects from one end of the housing 139 and has a sprocket 143 (part of aforementioned double sprocket 117) secured thereto over which the aforementioned drive chain 118 passes which is actuated by drive chain 114 from the main power source. Thus upon actuation of the motor 111, drive shaft 141 will be rotated. At its other end 144, drive shaft 141 has a circular cam member 146 secured thereto. As best seen in FIGS. 8 and 10A, 10B, and 10C, cam member 146 has a radial groove 147 in the outer face thereof.

Projecting from the other end of the housing is a driven shaft 149 having a sprocket 151 on the outer end thereof over which its associated drive chain 127 passes which is connected with its associated lug chain actuating shaft 83. At its inner end within the housing 139, driven shaft 149 has mounted thereon a circular cam follower 152. Projecting longitudinally from the cam follower adjacent its periphery is an offset follower pin 153 which is received in the elongated radial slot 147 of the cam member 146. The cam pin and slot thus interconnect drive shaft 141 and driven shaft 149 for rotation.

As mentioned previously, the bearing block 136 is mounted on guide rails 137 and 138 for lateral adjustment. From FIGS. 6 and 7 it should be understood that such adjustment is effected by a screw member 156 which is threadedly engaged in a threaded bore 157 extending through the bearing block adjacent the top thereof. Opposite ends of the screw member are rotatably but fixedly supported in suitable fluid tight bearings 158 and 159 in opposing side walls of the housing 139. An adjustment control wheel 161 is secured to one end of screw member 156 externally of the housing so that the screw member may be rotated in opposite directions to draw the bearing block towards or away from a given one of the side walls of the housing. Thus, the bearing block may be moved in one of two directions away from a neutral position in which the axes of the drive shaft 141 and the driven shaft 149 are coincident.

Such a neutral relationship in which the shaft axes are coincident and in which the follower pin 153 is centrally located in slot 147 is shown in FIG. 10A; this coincident axial relationship is also shown by the dotted line 162 extending centrally of FIG. 7. However, upon actuation of the adjustment control wheel 161, the bearing block may be moved toward the right side 'wall of housing 139 some predetermined degree, as seen in FIG. 10B. As shown by the dotted line 163 in FIG. 7 such movement effects transverse offsetting of the movable axis of the drive shaft 141 relative to the fixed axis of driven shaft 149 for a purpose to be described. Further movement of the control wheel 161 will result in the bearing block being moved further to the right as seen in FIG. 10C so that the axis of the drive shaft is further laterally offset, as illustrated by line 164 in FIG. 7, relative to the axis of driven shaft 149.

During lateral adjusting movement, it should be understood that follower pin 153 of cam follower 152 moves within the slot 147 of the cam member 146. It should also be understood that movement of the bearing block to the left from neutral location of FIG. 10A may be effected by rotating the control wheel in the opposite direction.

When the axes of the drive shaft 141 and driven shaft 149 are coincident, driven shaft 149 and chain 127 actuated thereby will be actuated at a constant predetermined speed determined by the speed at which drive shaft 141 is rotating. However, upon offsetting the drive shaft 141 relative to the axis of the driven shaft 149, the driven shaft will rotate at a non-constant speed. That is, the driven shaft will periodically and alternately speed up and reduce speed during each revolution thereof due to the offset axial relationship described. It is such non-constant rotation of the driven shaft which effects the periodic increase and decrease in the speed of rotation of the lug chains driven thereby so that the lugs carried by such chains may be moved into and out of engagement with the marginal portions of a carton blank being folded.

In this regard, it should be understood that 'when driven shaft 149 is actuated in non-constant fashion it in turn moves its associated drive chain 127 at a non-constant or interrupted speed. As previously described, drive chain 127 activates shaft 83 (FIGS. 1 and 2) which in turn activates lug chains 77 keyed thereto in similar non-constant interrupted fashion.

The companion drive mechanism 106 at the first folding station is similarly constructed and actuated to drive its associated shaft 79 and the lug chains 76 keyed thereto at non-constant changing or interrupted speed. By properly adjusting the respective mechanisms 106 and 107 with a predetermined degree of axial offset, determined by the size of the carton blank being folded, the folding lug members 73 and 74 may be actuated in proper fashion for effective folding as previously described.

The lateral adjustment of drive shaft 141 of each drive mechanism is not precluded by the aforementioned drive chains 118 and 119, FIGS. 2 and 11, because suitable idler sprocket tension means, shown schematically at 165 in those figures, permits such lateral adjustment while maintaining tension on the chains.

The other drive mechanisms 108 and 109 at the second folding station are similarly employed to actuate their associated lug chains 91 and 92 to produce the non-constant speed actuation of such lug chains to produce the desired folding at the second station.

The amount of speed variation and its direction is regulated in accordance with the degree of and direction of lateral shifting of the bearing block of the respective drive mechanisms. By suitably adjusting the wobble shaft structures of each of the drive mechanisms at each of the folding stations mentioned, the apparatus may be adapted easily and rapidly to accommodate cartons of various sizes.

It should be understood that the housing of each of the drive mechanisms is fluid tight and is filled with a suitable transmission fluid. Leakage through housing end plate 166 through which driven shaft 149 projects is easily precluded by means of a suitable bearing packing 167. Leakage through the opposite end plate 168 is somewhat more diflicult to obviate because of the lateral shifting of the drive shaft 141 which projects therethrough. In this regard, as seen in dotted lines in FIG. 7 the end plate 168 is provided with a laterally extending elongated slot 169 within which the drive shaft 141 is laterally movable. Slot 169 also has been shown in FIG. 9 in dotted lines for purposes of illustration even though the end plate is not shown in that figure.

interposed between end plate 168 and the end face 171 of the bearing block is an oval sealing ring 172 which is received partially within a correspondingly shaped groove in the end face 171 of the bearing block. See FIGS. 7 and 9. Thus as the bearing block moves laterally from side to side the oval sealing ring moves therewith. The lateral dimension of the sealing ring is sufiiciently large so that in all positions of adjustment of the bearing block the slot 169 in end plate 168 will be surrounded by the oval ring to preclude fluid leakage therethrough.

While hereinbefore this invention has been described in conjunction with the folding of opposed marginal portions of a paperboard carton blank having a particular configuration it should be understood that the apparatus and method hereof are utilizable in conjunction with numerous other carton blanks having substantially different configurations and folding arrangements than the carton shown. In this regard, utilization of this invention also is contemplated in conjunction with the infolding of carton portions which are not marginally opposed as shown herein; that is, in which all portions to be folded lie generally along the same margin of a carton blank, or intermediate opposed margins thereof. Also, this invention is usable in folding carton portions which are opposed but in which folding is not simultaneously effected as illustratively described herein. Depending upon the type of article to be handled, the folding members will be suitably oriented and such orientation, as should be obvious, may be widely varied to meet varied needs because of the adjustable characteristics of the respective operational components of the apparatus.

Having thus made a full disclosure of the method and apparatus of this invention and its utilization in conjunction with the handling of a particular illustrative article, reference is directed to the appended claims for scope of protection to be afforded thereto. In this regard, modifications to the preferred embodiment disclosed herein which fall within such scope are contemplated as part hereof in that the matter disclosed herein is intended to be illustrative rather than limiting.

I claim:

1. A method of folding portions of a flat sheet, comprising:

(A) moving said sheet at a predetermined speed along a fixed path in a given direction to and past a folding station,

(1) said sheet portions to be folded being arranged generally in leading and trailing relationship relative to each other,

(B) at said folding station providing a pair of cooperable opposed folding members,

(C) moving said members past said station generally in the same direction as said sheet with said members traveling in line with said sheet portions to be folded,

(D) positioning said sheet between said members at said folding station while continuing movement of said sheet and said members therepast, and

(E) as said sheet moves past said folding station increasing the speed of that one of said folding members which is adjacent the trailing sheet portion to a speed which is greater than said predetermined speed of said sheet, and generally simultaneously decreasing the speed of the other of said folding members to a speed which is less than said predetermined speed, whereby said folding members are drawn towards each other generally in scissors fashion and thereby are brought respectively into engagement with said trailing and leading sheet portions which are folded by said members without altering the path or the predetermined speed of movement of said sheet.

2. The method of claim 1 which further includes (F) decreasing the speed of said one folding member after such member has folded its associated sheet portion to a speed which is less than said predetermined speed, and also increasing the speed of said other folding member after such member has folded its associated sheet portion to a speed which is greater than said predetermined speed, whereby said folding members are drawn away from each other generally in scissors fashion and are thereby freed from engagement with said folded sheet portions.

3. method of folding a pair of panels of a fiat carton,

comprising (A) moving said carton at a predetermined speed along a fixed path in a given direction to and past a folding station,

(1) said pair of panels to be folded being arranged in leading and trailing relationship respectively relative to a carton reference panel,

(B) at said folding station locating said carton generally between a pair of folding members without altering the speed of said carton,

(C) moving said folding members in the same direction as said carton in line with said pair of panels at a speed corresponding generally with the speed of said carton, and

(D) as said carton moves past said folding station increasing the speed of that one of said folding members which is adjacent said trailing panel to a speed which is greater than said predetermined speed of said carton, and generally simultaneously decreasing the speed of the other of said folding members to a speed which is less than said predetermined speed of said carton,

whereby said folding members are drawn toward each other and said pair of panels are engaged and folded by said folding members inwardly toward said carton reference panel without altering the path or speed of said carton.

4. The method of claim 3 which includes (E) partially prefolding said pair of panels along predetermined fold lines before said carton reaches said folding station to facilitate folding thereof at said station.

5. The method of claim 3 which also includes folding a pair of flaps of said carton, said method including (E) moving said carton from said first mentioned folding station to and past a second folding station without changing direction or speed of movement thereof,

(1) said pair of flaps to be folded being arranged in leading and trailing relationship respectively relative to a second carton reference panel,

(F) at said second folding station locating said carton generally between a second pair of folding members separate from said first mentioned pair of folding members without altering the speed of said carton,

(G) said second pair of folding members moving in the same direction as said carton in line with said pair of flaps at a speed corresponding generally with the speed of said carton, and

(H) as said carton moves past said second folding station increasing the speed of that one of said second pair of folding members which is adjacent said trailing flap to a speed which is greater than said predetermined speed of said carton, and decreasing the speed of the other of such folding members to a speed which is less than said predetermined speed of said carton,

whereby said second pair of folding members are drawn toward each other and said pair of flaps are engaged and folded by said second pair of folding members inwardly toward said second carton reference panel without altering the path or speed of said carton.

6. A method of folding a fiat paperboard or like carton,

said carton in the fiat state comprising (1) a bottom panel,

(2) a first pair of side wall panels hingedly connected along opposite margins of said bottom panel,

(3) a pair of tabs hingedly connected at opposite ends of each panel of said first pair of side wall panels,

(4) a second pair of side wall panels hingedly connected along other opposite margins of said bottom panel, and

(5) a pair of flaps hingedly connected at opposite ends of each panel of said second pair of side wall panels,

said method comprising (A) moving said carton to and past a folding station at a predetermined continuous speed with said first pair of side wall panels arranged in leading and trailing relationship,

(B) as said carton moves to and past said folding station holding said carton down while maintaining said first pair of side wall panels and said tabs thereon free for folding,

(C) at said folding station, locating said carton between a pair of folding members which are moving generally in line with said first pair of side wall panels and at a speed which corresponds generally with the speed of said carton,

(D) as said carton moves past said folding station, in-

creasing the speed of that one of said folding members which is adjacent said trailing panel to a speed which is greater than said predetermined speed of said carton while generally simultaneously decreasing the speed of the other of said folding members to a speed which is less than said predetermined speed thereby to draw said folding members together in scissors fashion thereby to restrict said carton between said folding members and to effect folding of said first pair of panels toward each other into overlying generally contacting relationship with said carton bottom panel,

(E) as said first pair of side wall panels are being folded, simultaneously folding each of said tabs thereon into overlying generally contacting relationship with their respective side wall panels, and

(F) thereafter decreasing the speed of said one folding member to a speed which is less than said predetermined carton speed while generally simultaneously increasing the speed of said other folding member to a speed which is greater than said predetermined carton speed as said carton passes from said folding station, thereby to free said carton from said folding members and to permit disengagement of said folding members from said carton.

7. The method of claim 6 which includes (G) moving said carton from said folding station at said predetermined speed and without changing its direction of movement to and past a second folding station,

(H) as said carton moves to and past said second folding station holding said carton down while maintaining said second pair of side wall panels and said flaps thereon free for folding,

(I) at said second folding station, locating said carton between synchronized second and third pairs of folding members which are moving generally in line with the respective panels of said second pair of side wall panels and said flaps thereon,

(J) as said carton moves past said second folding station, moving one folding member of each of said second and third pairs of folding members at a speed greater than said predetermined speed of said carton while generally simultaneously moving the other folding member of each of said second and third pairs at a speed less than said predetermined speed thereby to restrict said carton between such folding members and to effect folding of said flaps on each of said second pairs of side wall panels toward each other into generally overlying relationship relative to their associated side wall panel,

(K) thereafter decreasing the speed of each of said first mentioned folding members of said second and third pairs while simultaneously increasing the speed of each of said last mentioned folding members of said second and third pairs as said carton passes from said second folding station thereby to free said carton from engagement with said second and third pairs of folding members, and

(L) thereafter folding each of said second pair of side wall panels with said flaps therewith into overlying contacting relationship relative to said folded first pair of side wall panels,

whereby said flaps on said second pair of side wall panels are engaged with and are adapted to be secured to said tabs on said first pair of side wall panels.

8. Apparatus for folding generally opposed portions of a fiat sheet, comprising (A) means for conveying said sheet at a predetermined speed along a fixed path to and past a folding station with said portions to be folded being arranged in leading and trailing relationship relative to each other,

(B) a pair of spaced folding members positionable generally in leading and trailing relationship relative to said sheet portions to be folded thereby,

(C) mechanism mounting said folding members for movement past said folding station generally in line with and along the same path as such sheet for relative movement with respect to each other, so that the spacing between said members may be periodically varied to bring said members alternately into and out of engagement with said portions of such sheet to effect folding thereof, and

(D) drive means for actuating said mounting mechanism with said folding members thereon in synchronization with movement of said sheet past said station but at changing speeds which are different from said predetermined speed of said sheet to bring said folding members into contact with said sheet portions to fold such portions generally inwardly toward each other without interrupting movement of said sheet or changing its path of travel.

9. The apparatus of claim 8 which includes (E) means for partially prefolding said portions of said sheet along predetermined fold lines before said sheet reaches said folding station.

10. The apparatus of claim 8 in which said mechanism mounting said folding members for movement comprises (E) a pair of side by side endless chains moving in closed paths at and generally past said folding station,

(1) each of said chains carrying one folding member of said pair of folding members thereon 1? with each such member projecting from its associated chain, said drive means of said apparatus including (F) drive mechanism operatively connected with said pair of chains for moving said chains in synchronization with a moving sheet and for alternately reducing and then increasing the speed of one of said chains While generally simultaneously and alternately increasing and then reducing the speed of the other e chain,

whereby the spacing between said folding members carried on said chains is alternately decreased and increased to effect sequential clamping and release of said sheet therebetween to effect folding of said portions thereof.

11. Apparatus for folding a portion of a flat sheet,

comprising (A) means for conveying said sheet at a predetermined speed along a fixed path to and past a folding station,

(B) movable folding means at and movable past said station locatable adjacent said sheet portion to be folded as said sheet is conveyed past said station, comprising (1) an endless chain moving in a closed path at and past said station,

(2) said chain carrying a folding member thereon which projects therefrom and is engageable with said sheet portion to be folded, and

(C) drive means moving said chain in synchronization with movement of said sheet past said station and alternately changing the speed of said chain to alternately increase and decrease the speed thereof to bring said folding member alternately into and out of contact with said sheet portion wihout interrupting movement of said sheet or changing its path of travel.

12. Apparatus for folding portions of a. series of flat sheets, such as carton blanks, in sequence, comprising (A) means for conveying said series of sheets in sequence and at a generally constant speed in a fixed generally straight path to and past first and second folding stations,

(B) first movable folding means at said first station locatable sequentially generally in advance of and behind the respective sheets to be folded to engage each sheet of said series to fold a first foldable portion of each such sheet without interrupting movement of such sheet as such sheet is conveyed past said first station,

(C) second movable folding means at said second station locatable sequentially generally in advance of and behind the respective sheets to be folded to engage each sheet of said series to fold a second foldable portion of each such sheet without interrupting movement of such sheet as such sheet is conveyed past said second station, and

(D) drive means for actuating said first and second Cir folding means in synchronization with movement of said series of sheets past said first and second stations but at changing speeds which are different from the speed of said series of sheets, thereby to bring such folding means sequentially into contact with the respective sheet portions to be folded thereby so that such sheet portions may be folded generally inwardly without interrupting movement of said series of sheets or changing their path of travel,

(E) each of said first and second folding means comprising mechanism which includes (1) at least one endless chain moving in closed path at each of said stations, and

(2) at least one folding member carried by and projecting from each said chain:

(F) said drive means comprising at least one drive mechanism adjacent each of said folding stations, each of said drive mechanisms including (1) a bearing block, (2) means mounting said beaming block for adjustable movement relative to a neutral location, (3) a drive shaft mounted on said block and movable therewith,

(a) said drive shaft being operatively connected with a source of power, (4) a cam on one end of said drive shaft, (5) a driven shaft, (6) means fixedly mounting said driven shaft for rotation,

(at) said driven shaft being operatively connected with a chain of an associated folding means to effect movement of such chain, (7) a cam follower on one end of said driven shaft engaged with said cam on said drive shaft, (8) the axes of said drive shaft and said driven shaft being in alignment when said bearing block is in said neutral location, said axes being offset relative to each other when said bearing block is moved from said neutral location, (9) means for adjustably moving said bearing block and said drive shaft therewith from said neutral location to effect offsetting of the axes of said shafts.

References Cited UNITED STATES PATENTS 2,953,070 9/1960 Dunning 93-84 X 2,839,972 6/1958 Labombarde 93-49 2,969,002 1/ 1961 Meyer-Jagenberg 9349 3,068,761 12/1962 Engleson 9349 3,138,075 6/1964 Martin 93-49 3,298,287 1/1967 Peterson 9349 3,330,185 7/1967 Annett 9349 WAYNE A. MORSE, JR., Primary Examiner. 

